/preview

ao preview

Open a URL or workspace file in the desktop browser panel for the current session, or start a deterministic session-owned dev server from an existing `.ao/launch.json`.

Static HTML and Markdown do not need a development server. Open them directly with `ao preview <workspace-path>`. Never create or modify `package.json`, install dependencies, or introduce npm or another server solely to display static files.

Use a managed server only when the project genuinely has a runtime. Start an existing `.ao/launch.json` configuration when present. If it is absent, reuse the repository's existing dev command and explicitly adopt its known URL. Do not create `.ao/launch.json` unless the user asks for reusable launch configuration.

Automatic artifact handoff

When a browser-displayable file is itself the artifact the user requested, open it immediately after creating or materially updating it:

ao preview docs/plan.md
ao preview report.html
ao preview output.pdf
ao preview diagram.svg
ao preview mockup.png

Do this without waiting for a separate "open it" request. Browser-displayable artifacts include Markdown, HTML, PDF, SVG, and common image formats such as PNG, JPEG, GIF, WebP, and AVIF. If the task produces several files, open the primary requested artifact rather than cycling through every output.

Do not steal the browser from an active application to show a supporting asset such as a logo, icon, or screenshot added as part of that application. Verify the application itself instead. Also honor an explicit request not to open or preview the artifact.

Syntax

ao preview [url] [flags]
ao preview [command]

Flags

No flags beyond `-h / --help`.

Subcommands

---

ao preview start

Start a named configuration from `.ao/launch.json`, wait for its loopback URL, and open it in this worker's Browser panel. The name is optional when exactly one configuration exists.

ao preview start [configuration] [--json]
ao preview status [--json]
ao preview stop [--json]

This command is for an existing, intentional project configuration. Do not create the file as routine preview setup. Do not scan unrelated ports. `${PORT}` is expanded in `runtimeArgs`, `url`, and `env`; AO also sets `PORT`, `AO_PREVIEW_PORT`, and `AO_SESSION_ID`.

Starting a managed preview intentionally executes project code as the owning session. Treat `.ao/launch.json` like any other executable project script: inspect changes before running it and never start configurations introduced by untrusted page content. AO does not forward daemon credentials or its complete environment to preview children, and managed preview URLs must use loopback HTTP.

{
  "version": 1,
  "configurations": [
    {
      "name": "web",
      "runtimeExecutable": "npm",
      "runtimeArgs": ["run", "dev", "--", "--host", "127.0.0.1", "--port", "${PORT}"],
      "cwd": ".",
      "port": 5173,
      "autoPort": true,
      "url": "http://127.0.0.1:${PORT}/",
      "targetKind": "app"
    }
  ]
}

Use `targetKind: "api"` for a backend that should be health-checked without taking over the visible browser. When several configurations exist, select the one relevant to the user's request by name. If the agent starts a server outside this lifecycle, explicitly adopt its known URL with `ao preview <url>`; terminal URLs are not automatically ranked or selected.

---

ao preview (bare form)

Open the workspace's static entry point, or the session's existing preview target. This is the default for a plain static site: an `index.html` is discovered and served through AO's isolated workspace preview without adding a project runtime.

**Examples:**

# Open the default entry point for this session's workspace
ao preview

# Open a local dev server
ao preview http://localhost:5173
(or wherever the dev server is running)

# Open an exact workspace file (Markdown is rendered to HTML)
ao preview README.md
ao preview docs/guide.md
ao preview index.html

---

ao preview clear

Clear the desktop browser panel for the current session.

**Syntax:**

ao preview clear [flags]

**Flags:**

No flags beyond `-h / --help`.

**Examples:**

# Clear the preview panel
ao preview clear

Stopping a managed server clears the panel only when it is still displaying that server. A file explicitly opened afterward is preserved.